In preparation to split the sprites from the stage, start managing the target list state in a single place.

Move behavior-related components to "containers", leave presentation components in "components".

While doing so:
- Use ProjectLoader for loading projects
- Stop using loadEmptyProject and supply empty project data
- Move project loading to App, GUI now receives data (as a string - the vm should receive an object eventually)
- Add logging

This way we can have a consistent style for Node and web code.

Thanks to babel-loader and babel-eslint, we can use the same linting everywhere.  This makes our imports easier since we don't need to think about the extension.

Also export things more succinctly in src/index.js